Algebra
posted by Jeannie on .
x + 9y=33
5x + 4y =1

Eq1: X + 9Y = 33.
Eq2: 5x + 4y = 1.
Multiply both sides of Eq1 by 5 and add the Eqs:
Eq1: 5X  45Y = 165.
Eq2: 5X + 4Y = 1.
Sum: 0  41Y = 164,
Y = 4.
In Eq1, substitute 4 for y:
X + 9*4 = 33,
X = 33  36 = 3.
Solution set: (X,Y) = (3,4).